New Los Vaqueros Reservoir filling up

Tom Stienstra, Chronicle Columnist

Updated 2:54 am, Sunday, January 27, 2013

Los Vaqueros Reservoir, extending from the new dam (center), is gradually rising toward its full level of 1,900 surface acres. Right now, it's at 68 percent of its new capacity.
Photo: Jim Freschi, Contra Costa Water District

Los Vaqueros Reservoir, extending from the new dam (center), is...

An overlook at newly expanded Los Vaqueros, where the fishing is already good and wildlife plentiful.
Photo: Jim Freschi, Contra Costa Water District

One inch at a time, the water level is rising at the new Los Vaqueros Reservoir. In the coming months, with the new dam complete, Los Vaqueros will be twice the size of any other recreation lake in the Bay Area.

Some are not waiting for that. Earlier this month, a pair of lucky anglers caught 25 trout in one day. Golden eagles are building nests. Bobcats are out hunting ground squirrels.

In the past few weeks, the level climbed past what used to be full for the old reservoir. It's now at 68 percent of the new capacity.

The new Los Vaqueros, when full, will be 1,900 surface acres, the centerpiece of a watershed that spans nearly 20,000 acres.

To put it in perspective, consider other well-known recreation lakes in the Bay Area: In San Francisco, Lake Merced South is 203 acres and Merced North is 105 acres. In Marin County, Alpine Lake is 224 acres. In Contra Costa County, San Pablo Reservoir is 866 acres. In Alameda County, Lake Chabot is 315 acres and Del Valle is 750 acres. And in Santa Clara County, Lake Anderson is 1,000 acres.

Of all the places you can go in California, I'm most transfixed by Los Vaqueros because of what is already happening - and what is possible: fish, wildlife and birds.

Yet many have still not seen Los Vaqueros. It is in deep valleys in the rolling hills roughly between Livermore and Brentwood in remote Contra Costa County. There are two access points: South Gate out of Livermore for the marina and trailheads for the best lake views and wildlife sightings; and North Gate out of Brentwood for the John Muir Interpretive Center and ranch roads for mountain biking and hiking out to the dam

Fish: As the lake fills, the amount of cover and the richness of the aquatic food chain will probably make this one of the top fishing lakes in California. Trout and striped bass are on the marquee, and a new program for bluegill and crappie will be established this year.

Trout fishing is good, with regulars getting their limits every time out, and some do better. This month, Al Hurwitz of Saratoga and Abbey Lev of Sunnyvale caught 25 trout, released 18 of them, with seven ranging from 1 1/2 to 4 1/2 pounds. They were trolling Rapalas five feet deep in 20 to 30 feet of water in the large inlet cove on the eastern shore near the dam.

But what could boggle the mind is the striped bass, which get pumped in with the water from the Sacramento-San Joaquin River Delta. The lake-record striper is already a 45-pounder. It's my experience that when the water temperature hits 57 degrees (it's 52 now), that's when schools of stripers form to corral and attack baitfish; you can cast to the school and catch-and-release five to 10 stripers in a session.

Wildlife: Sightings of bobcats and coyotes have been higher this month at Los Vaqueros than at any other watershed, preserve or park in the Bay Area. The reason is the high number of ground squirrels and rabbits. Predators always have something to hunt there, and so they're out a lot, visible to many, hunting. If you hang around much at Los Vaqueros, sooner or later you'll see a bobcat trotting down the road with a squirrel in its mouth. "There's so much wildlife and birds, three times what I see at the other places," said longtime field scout Chris Senti, who runs the marina and has worked at many lakes in the Bay Area and Northern California

Birds: Last spring, in a series of successful golden eagle nests, eight juvenile goldens were verified to fledge - that is, to learn to fly and hunt. This year, with heavy December rains and improved habitat conditions, numbers could be even higher. In addition, it is common to see red-tailed hawks, kestrels and, if you know how to identify them, prairie falcons and peregrine falcons. Though bald eagles have not established residence yet (there are eight nesting pairs in the Bay Area), they are common visitors. The best spot to look for bald eagles is in the scraggy trees north of the marina above the West Fork of Kellogg Creek, where the eagles often perch to watch for fish.

Events: Guided nature tours, including boarding a patio boat for bird watching, are scheduled Fridays through Sundays; see www.ccwater.com/losvaqueros/.

Weird rules: A series of inexplicable rules are in effect that include: no private boats or swimming (even though the adjacent delta, where the water comes from, is full of boats and water sports), no leashed dogs (even though cows graze in the watershed).

How to get there

South Gate: From San Francisco, take Interstate 80 over the Bay Bridge to the split and bear right on I-580. Continue east on I-580 for 37 miles to Livermore and beyond to Vasco Road. Take Vasco Road north 4.5 miles to Los Vaqueros Road (look for small brown watershed sign). Turn left and drive to South Gate entrance station, then continue to parking, marina and trailheads.

North Gate: In Contra Costa County, take Highway 4 east to Antioch (past Hillcrest) and merge left onto the Brentwood Bypass and continue to Walnut Boulevard. Turn right on Walnut and drive a mile to North Gate entrance station, then continue to parking, interpretive center and trailheads for access to dam.